Is expiation incumbent upon one who swore by Allah not to imagine certain matters related to intercourse and a specific person, then later re-imagined them, given that she suffers from obsessive-compulsive disorder and cannot recall whether she did so out of forgetfulness or intentionally? And what is incumbent upon her if expiation is due, but she is unable to feed a poor person or free a slave?

"You are not required to offer expiation for breaking an oath because, according to the preponderant opinion, performing an action that one swore to abandon out of forgetfulness does not break the oath. Do not pay attention to doubts, as they appear to be whisperings (waswas); certainty is not removed by doubt. Similarly, doubt concerning the original oath, whether it occurred or not, does not necessitate anything, as the default is the absolution of one's responsibility. We advise you to continue repelling fantasies in general, especially if they relate to a specific person, for this is impermissible."